Thermoactive wall and ceiling element

ABSTRACT

The thermoactive wall and ceiling element is installed in walls of newly built and old buildings and serves for its heating and cooling. It consists of a closed casing ( 2 ) which for intermediately storing heat comprises a phase change material ( 3 ) which melts when accommodating heat and reversely delivers latent heat to the surrounding on solidification. A lamellar design ( 8 ) with sound-absorbing material ( 4 ) therebetween is hung on this casing in a thermally separated manner by way of a heat-insulating material. At the bottom the lamellar design ( 9 ) is closed by a perforated ceiling sheet [metal] (plate) ( 5 ) in a heat-conducting manner, and this sheet metal (plate) forms the viewed ceiling of the room. The lamellar design encloses a heating and cooling pipe which is outwardly formed by the lamellar design as one piece or is connected to it is a heat-conducting manner. A displaceable heat-conducting heat contact body ( 24 ) is installed in the cavity ( 23 ) between the lamellar design ( 8 ) and the casing ( 2 ), and this body with all its parts creates a heat connection between the casing ( 2 ) and the lamellar design ( 8 ). An air gap ( 27 ) to the casing ( 2 ) arises, depending on its position, so that a thermal separation is achieved by it.

This invention relates to a thermoactive wall and ceiling element forinstallation in rooms of new buildings, and in particular old buildings.The wall and ceiling element is to contribute to a rational use ofregenerative energy sources in order to adapt the room climate to therespective requirements in a more efficient and cost-saving manner. Theelement is suitable for lightweight constructions, such as for woodenconstructions or constructions according to other lightweightconstruction systems. With regard to this, it is insignificant as towhether the ceiling element is installed in residential houses, that isto say detached or multiple dwelling houses, or in commercial buildingsor industrial buildings. Basically, the element may be applied whereverrooms are to be cooled and/or heated. Commercially used buildings inparticular always have building shells with an improved thermalinsulation. When rebuilding and renovating, the facings (facades) arenewly designed, better insulated and one incorporates considerablylarger window areas in order to achieve very bright rooms and to givethe building a lighter, more elegant and modern aesthetic appearance.New buildings are built from the very outset so as to have as good aspossible heat insulation properties. At the same time however the use ofincreased technology is becoming more and more prevalent in suchbuildings. Indeed it is irrelevant as to whether the users of thebuilding are merely in the service industries and perform only officework or whether they also for example carry out their work in technicallaboratories, or also other commercial or even industrial activities.Increasing numbers of electrical apparatus are installed which allinevitably produce heat These various heat-producers are copy apparatus,computers, and printers, fax apparatus, televisions, video means,telecommunication means, but also refrigerators, coffee machines,cleaning machines etc. Last but not least, each person present in theroom is also a heat source due to his or her body temperature andcontributes to the heat load. In the future therefore, on account of thebuilding shells which are becoming thermally better insulated, and theinternal heat loads due to the increased use of technical apparatuswhich have just been mentioned, it is therefore the cooling and notnecessarily the heating of such buildings which will come to theforefront. The heat management is shifting in this direction also withregard to residential buildings.

The transport of heat away from the rooms may be effected in twodifferent manners: Either the excess heat is transported awayimmediately or directly on its occurrence to a cooling system, or theexcess heat is transported into an intermediate reservoir so that it maybe exploited again at a later point in time when required, or isotherwise definitively led away to the surroundings outside the roombeing considered. The first variant requires water or another coolantwhich must be available for the time during which the heat occurs, e.g.during the working hours. A compression refrigerator may only mostlycool this during the hot part of the year. The second variant, that isto say the temporary intermediate storage of excess heat may be realisedin various ways and offers the following possibilities: Firstly naturalheat sinks may be used for leading away the heat, for example at night,to the cold air of the surroundings via a heat exchanger, whosetemperature then of course increases again during the day, or however apermanent heat sink is created by way of an earth probe or earth piles,whose temperature always remains roughly the same and which whenrequired may be used as a heat source, wherein specifically thegroundwater serves as such a heat source and heat sink depending onwhether one wishes to cool or to heat. It is the improved use ofregenerative energy sources, which is at the forefront with the presentinvention, in that by way of the intermediate storage of heat, the timedifference between the demand for regenerative energy and the supply isto be compensated. The use of a refrigerator may also be considered as afurther possibility which is used for cooling the air during the day butis used for cooling the room at night. This variant also allows the peakcooling output of a refrigeration installation to be significantlyreduced since the full cooling output does not need to be made availableimmediately, but may be distributed over a longer period of time, forexample 24 hours, on account of the possibility of the intermediatestorage. With new buildings, the building mass may be used as a thermalintermediate reservoir by way of pipes in the core of the buildingcomponent, and may be economically managed in an optimal manner. This ishardly possible with conversions since the ceiling structure is alreadypresent and thus pipes may only be installed with an extraordinarilylarge expense. Furthermore in such rooms there are mostly suspendedceilings which on the one hand conceal the ceiling installations and onthe other hand assume sound insulation functions. In order despite this,to be able to cool the room in an efficient manner, the existing doubleceiling is replaced by a cooling ceiling.

Cooling ceilings which may be cooled with water are known. They consistessentially of sheetmetal plates, mostly of steel, stainless steel oraluminium which are assembled on heat conducting rails in the form oftube sections by way of a snap mechanism which have been previouslyinstalled on the ceiling by way of a mounting system. These tubesections are aluminium-extruded sections in which a copper pipe ispressed in a good heat-conducting manner. These tube sections aremounted on a cooling circuit and water may flow through these. After theassembly on a ceiling, these sections have limbs and feet projectingdownwards which when sheetmetal plates have been attached from below,bear on the upper side of the plates in a flush manner and form a heatbridge. The for assembly are equipped on their upper side with aclamping section which may be clicked into spring-steel clips on thepipe section which are open to the bottom The sheetmetal plates may becoated or anodised or may be plastered or glued on the building(construction) site. For improved sound insulation, one has often usedperforated sheetmetal plates with sound absorption material arrangedbehind this.

Cooling ceilings of modules capable of being folded away are also known.With these, the sheetmetal plates of steel, stainless steel or aluminiumacting as cooling elements are equipped with cooling pipe systems whichare assembled on these. These modules on one side are then pivotallyarticulated onto system sections which were previously assembled on theceiling. After connecting the cooling pipe system to a cooling circuit,the modules may be pivoted up and secured in the horizontal position byway of a snap mechanism or by way of securing screws or securing pins.

A further known cooling ceiling system consists of individual smoothsurfaced or perforated panels of aluminium sheet metal parts which arefolded at the edges on all sides. In the folded edges, in thelongitudinal direction of the edges, there are provided contact surfacesfor zinc-coated pipe conduits which are fastened on the contact surfacesby way of steel clips. The pre-manufactured assembly units are fastenedon the pipe ceiling with tie rods and when required may be equipped withacoustic plates at the top or on the lower side for achieving animproved sound insulation, which however reduces the cooling performancesomewhat.

There are finally solutions with which a cooling pipe system isinstalled on a ceiling in that the cooling pipes from below are clickedinto U-sections open at the bottom which were previously assembled onthe ceiling. Then from below sheet metal panels filled with soundinsulation material are suspended between the U-sections, and thesepanels on their lower side comprise a laterally projecting edge so thatthe cooling pipes and the assembly section are covered. A thermoactiveceiling element is known from JP 07 293908 A, which comprises a closedcasing which for the intermediate storage of heat contains phase changematerial as a latent heat reservoir, wherein the heat exchange ifeffected via a heating and cooling tube. A microencapsulated phasechange material is disclosed in U.S. Pat. No. 5,435,376 but however nothermoactive ceiling element. The thermoactive ceiling elements whichhave been known up to now, although functioning in principle, howeverhave the deficiency that the heat exchange is effected far toosluggishly since the water carrying the heat only comes into contactwith the phase change material at a small surface. Furthermore theseceiling elements are questionable with regard to fire technology whenone considers the danger which paraffin entails. Finally the knownthermoactive ceiling elements also lack measures for sound protection,although they indeed act in a sound-reflecting manner.

The disadvantage with all these known systems is the fact that theirheat capacity is relatively low and thus the heat may not beintermediately stored during the cooling, but must be led away directlyto the coolant. In other words: these ceiling elements serve merely toaccommodate the heat in an efficient manner and lead to it directly tothe cooling pipe system, but not however to temporarily intermediatelystore the heat.

It is therefore the object of the present invention to specify athermoactive wall and ceiling element for heating and cooling rooms innewly built and old buildings, including lightweight constructionbuildings, which overcomes all those disadvantages mentioned above. Inparticular it should not only permit the direct leading away of heatfrom the room but also permit it to be temporarily intermediately storedso that the heat may flow away to the surroundings which later havebecome colder, such as the surrounding air which at night acts as anatural heat sink, with a time delay with respect to the accumulation ofheat. The stored heat may also be used again if required. Furthermorethis thermoactive wall and ceiling element is to have a smallconstruction height, is to be economical in manufacture and is should beable to be very easily installed in the building. It is to be able to beused in a comprehensive manner and should be able to be incorporatedinto old buildings as well as new buildings in a manner being compatiblewith their architectural concept. If necessary it should also have goodsound insulation properties. Furthermore, in a particular embodiment, itshould fulfil fire safety standards such that it meets the fire safetyregulations set by the authorities.

This object is achieved by a thermoactive wall or ceiling element forconstruction (installation) in rooms of newly built and old buildings,including lightweight construction buildings, in that it comprises aclosed casing which contains a phase change material as a latent heatreservoir for intermediately storing heat, as well as at least oneassociated heating and cooling pipe for controlling the heat exchangebetween the casing and its surroundings, wherein the casing forintermediately storing heat contains a phase change material which isbased on normal paraffin or a salt hydrate and for increasing thethermal conductivity in the region of the phase change material, in itsinside, is either equipped with heat conducting ribs and/or graphite isadded to the phase change material, for increasing the heat conductioncapability, and which is characterised in that in the inside of thecasing heat-conducting ribs are arranged in heat-conducting contact withthe casing, between which the heating and cooling pipes (tubes) of acapillary tube mat extend, whose connections are led through the lid ofthe casing for insert (plug-in) connections, and that the remaininginside of the casing of cast out (filled) with a plaster as a carriermass in which phase change material encapsulated in plastic capsules isdispersed, as well as that a viewed ceiling element is arranged on thelower side of the casing.

Advantageous embodiment of this thermoactive wall and sealing elementare to be deduced from the dependent patent claims. Various variants ofthis thermoactive wall and ceiling element are presented by way of thedrawings, and these are described in detail and their function explainedin the subsequent description.

There are shown in:

FIG. 1 a first variant of a thermoactive wall and ceiling element shownin a cross section, with which the heating and cooling pipe runs outsidethe casing in a lamellar design which is filled with sound absorptionmaterial and carries the ceiling sheet [metal] (plate), wherein thislamellar design is interruptibly heat-conductively connected to thecasing;

FIG. 2 a second variant of a thermoactive wall and ceiling element shownin a cross section, with which the heating and cooling pipe run outsidethe casing in a lamellar design which is filled with sound absorptionmaterial and carries the ceiling sheet [metal] (plate), wherein thislamellar design is interruptibly heat-conductively connected to thecasing;

FIG. 3 a third variant of a thermoactive wall and ceiling element shownin cross section, with which the healing and cooling tube is integratedinto the casing material and runs in the inside of the casing, and whichon the room side is equipped with sound absorption material;

FIG. 4 a fourth variant of a thermoactive wall and ceiling elementsshown in a cross section, which on the room side is equipped with soundabsorption elements and with which the heating and cooling pipe runs ina heat-conducting manner in a channel in the lower side of the casingalong its outer side and is connected in a heat conducting manner to theceiling sheet [metal] (plate) on the room side;

FIG. 5 a fifth variant of a thermoactive wall and ceiling element shownin a cross section, with which the heating and cooling pipe isintegrated in the casing material and the sound insulation material isarranged above the casing;

FIG. 6 a sixth variant of a thermoactive wall and ceiling element shownin a perspective view, with which the heating and cooling pipes areformed by a capillary tube mat which is integrated into the casingmaterial;

FIG. 7 a first variant of a mounting device for such wall and ceilingelements;

FIG. 8 a second variant of a mounting device for such wall and ceilingelements;

FIG. 9 a seventh variant of a particularly fireproof thermoactive walland ceiling element shown in a perspective view, with which the heatingand cooling pipes are formed by a capillary tube mat withmicroencapsulated PCM dispersed in plaster.

The thermoactive wall and ceiling element is firstly described by way ofFIG. 1. It consists essentially of a closed casing 2 of heat-conductingmaterial which is filled with a phase change material 3, as well as of alamellar design 8 with a heating and cooling pipe 1 and with a viewedceiling element 5, wherein all these elements are actively connected toone another with regard to heat technology, as well be explained later.In the shown example, with regard to the casing 2 it is the case of asheet [metal] section with a lower side which seen in cross section runsto the upper side in an oblique manner, wherein this sheet [metal]section encloses a cavity in that it is closed in a fluid-tight mannerto the front and rear with a lid (cover) in a fitting manner. This sheet[metal] casing 2 is advantageously manufactured of aluminium for reasonsof weight, even if steel sheet metal, chrome steel or other nonferrousmetals are considered as a manufacturing material. The casing 2 may alsobe manufactured of a suitable plastic which with a low wall thickness islikewise good at conducting heat. The phase change material 3 is eitherused in it pure form or is included in a carrier material. The sheet[metal] casing may contain a separate supply and discharge connection sothat the phase change material 3 may be filled later in a liquid form ormay also be removed again so that an later retreat working may beaccomplished in a simple manner. Here a lamellar design 8 is constructedbelow the casing 2 and this design forms a number of rib-like lamellae 9between which a sound-absorbing material 4 is accommodated. Thislamellar design 8 is fastened peripherally to the body 2 via side-walls22 which are manufactured of good heat-insulating material and thus actas thermal separation walls 22. Thus a cavity 23 is formed between thecasing 2 and the lamella design 8, within which a good heat-conductingheat contact body 24 wedge shaped in cross section is installed. Here,this lies on the upper side of the lamellar design 8 in a displaceablemanner and is connected to this design in a heat-conducting manner. Thiswedge-shaped heat contact body 24 for example is an aluminium solidmaterial body or it consists of an aluminium sheet [metal] hollow bodywhich is filled with a good heat conducting metal wool or a metal foamfilling. On the higher side of its wedge shape there are arranged drivemeans 26 by way of which the heat contact body 24 in the cavity 23 maybe horizontally displaced to and fro. If in the picture it is displacedcompletely to the left then a heat-conducting connection of its upperside to the lower side of the casing 2 which is provided with a contactlayer 28 is effected, and thus depending on the prevailing temperaturegradient at this moment, heat may flow to and fro between the casing 2and the lamellar design 8 and the viewed ceiling element 5 fastenedthereon, which for example may be a perforated sheet [metal] (plate). Ifhowever the heat contact body 24 is displaced completely to the right asis shown in the picture, then an air gap 25 arises above it whichthermally separates it from the casing 2. The thermal separation may beencouraged by a low-ε-coating of the lower side of the casing and theupper side of the heat contact body 24 for reducing the heat radiationin the long-waved region.

The drive means 26 advantageously consist of one or more electrochemicalactuators. With such an electrochemical actuator, amongst other thingsknown under the initials ECA, it is the case on the one hand of thecombination of an expansion element as pneumatic components and on theother hand of a battery as an electrochemical component for producinggas in a controlled manner. The battery with nickel hydrogen cells, byway of the supply and discharge of constant current at a low voltage ofapprox. 2 Volts may reversibly produce and consume hydrogen which thenfeeds an expansion element in the form of a metal bellows. Such ECAs arevery suitable as regulation elements and specifically as positioningmeans since they are characterised by good control properties and withsmall construction sizes may muster large forces with a low energyconsumption, and to top it all they function completely without noise.In comparison to motor drives, they require no peripheral equipmentsince the necessity of having to convert a rotational movement into atranslatory movement does not exist. Holding conditions may be used inevery position of the regulation path. The supply of low charges leadsto very small regulation movements which can be detected by a pathsensor. The regulation speeds without load are approx. 0.1 mm/s to 1mm/s and the typical inner pressures of ECAs lie in the region of 4 barto 50 bar. Electroactive polymers are suitable as further drivevariants, which on application of an electrical field undergo a lengthextension, or also electroreological fluids or hydraulic or magneticforce cylinders may be suitable as drive means.

At least one heating and cooling pipe 1 runs in the inside of thelamellar design 8 which advantageously consists of a sectionmanufactured with the continuous casting method. This heating andcooling tube 1 serves for the management (running) of the completethermoactive wall and ceiling element. The flow channels of severalindividual wall and ceiling elements, said flow channels being formed bythe heating and cooling pipes 1, are connected to one another onassembly, such as by way of soldering or by way of pipe bows (bends)capable of being coupled, or flexible tubing connections. A single suchwall and ceiling element given a defined section width is advantageouslymanufactured in defined system lengths; for example 1 m, 2 m and 3 mlength The section width is limited by the maximal assembly weight. Thelengths are determined such that the peripheral extent of the elementstill remains manageable and they may be easily carried around on thebuilding site and installed by two fitters.

A second variant of a thermoactive ceiling and wall element is shown inFIG. 2 which with many parts is constructed identically to that of FIG.1, specifically likewise with a casing 2 which is filled with a phasechange material 3 as well as with a lamellar design 8 which is thermallyseparated from the casing 2 and which is connected to the casing 2 viaside walls 22 of good heat-insulating material running in a peripheralmanner. The lamellar design 8 is closed with a viewed ceiling element 5and accommodates a sound-absorption material 4 between its lamellae 9.In contrast to the design according to FIG. 1, here the control of theheat flow between the casing 2 and the lamellar design 8 is solved in adifferent manner. Here, a good thermally conductive and elasticallycompressible heat contact body 24 is installed in the cavity 23 betweenthe casing 2 and the lamellar design 8. This for example consists of asuitable heat conducting polymer. A movement sheet [metal] (plate) 25runs within this body 24 or on its upper side, and may be moved upwardsor downwards in a parallel manner and at the same time moves the heatcontact body 24 with it. If the movement sheet [metal] (plate) 25 whichin the example shown here runs within the heat contact body 24 isbrought into its uppermost position, then the heat contact body 24connects to the lower outer side of the casing 2 and a heat-conductingconnection to this is effected. If however the movement sheet [metal](plate) 25 is brought into its lowermost position, then the heat contactbody 24 is compressed and an air gap arises between its upper side andthe lower side of the casing 2. This air gap acts in a thermallyinsulating manner so that the lamella design 8 to a great extent isthermally separated from the casing 2. The compression and expansion ofthe heat contact body 24 in the shown example is solved by way of thismovement sheet [metal] (plate) 25 which for its part is accomplished bythermoelectric drive means 26, electric motors, hydraulically ormagnetic force cylinders but also electrochemical actuators ECA orelectroactive polymers (EAP) which as shown here are fastened to theouter side of the casing 2.

The appropriately required thermal separation of the casing 2 from thelamellar design 8 with the viewed ceiling element 5 fastened on thelower side of this lamellar design may also be realised with furtherdesign variants. For example a number of good thermally conductivematerial bridges may be provided in the cavity 23 between the casing 2and the lamellar design 8 which may then be interrupted similar toelectronic switches, wherein this interruption and closure may beeffected in an electrical manner. In a further variant, electroactivepolymers EAP may be used as a drive means for the deformation of theelastically compressible heat contact body, and these may be arranged inthe inside of the heat contact body 24. They are electrically actuatedand expand when supplied with current and contract again when thecurrent is led away so that when required an air gap may be producedbetween the heat contact body 24 and the casing 2.

As already mentioned, a phase change material 3 is located in the insideof the casing 2 which forms an essential component of these ceiling andwall elements. Such materials have a particularly high melt enthalpy andare known as PCMs, which is an abbreviation for phase change material.They preferably comprise paraffis. Paraffin is a collective term forsaturated hydrocarbon mixtures which are mainly extracted from crudeoil, are a by-product of lubrication oil manufacture, and are alsocalled waxes. They are organic substances which after refining areodourless, tasteless and non-toxic. Paraffins are substances which aresuitable for thermal applications on account of favourable chemical andphysical properties. Their technical handling is not a problem. Onedifferentiates between normal paraffins and iso-paraffins. Normalparaffins consist of simple, long-chain molecules. Iso paraffins incontrast have molecules with a long basic chain and branches branchingfrom this. Normal paraffins are used for applications with regard tothermal technology as are present here. The chemical total formula forparaffin is C_(n)H_(2n+2). For paraffins with a melting temperaturebetween 20° C. to 90° C., the number n lies between 17 and 50. Themelting temperature of the material increases with an increasingmolecular chain length or increasing molar mass. PCMs may be conditionedto the desired melting temperatures in accordance with the desiredapplication. The phase change material based on paraffin used here,apart from a high specific heat capacity has a melting temperature of20° C. to 24° C. which corresponds to usual room surface temperatures.Ideally the phase change material at a melting temperature of approx.22.5°C. should have a specific heat capacity of at least 35 kJ/(kg K).The specific heat capacity at 21° C. or 24° C. should amount to at least55% of the maximal value of the complete PCM filling given a substancedensity of 900 kg/m³ (PCM graphite mixture). Apart from the sensitive,thus perceivable heat which such a material releases, also in particularthe latent heat which has been stored during the melting phase is againreleased during the solidification phase. The liquefaction as well asthe solidification is effected in a restricted temperature range forexample within 4-5K. If other room temperatures are to be maintained,which differ greatly from those which are common, then a suitable phasechange material with suitable characteristics is selected. Theparticular advantage of a PCM lies in the exploitation of the latentheat during the phase change. Salt hydrates also act as a phase changematerial, such as sodium acetate trihydrate or sodium sulphate(mirabilite).

In order to efficiently exploit the advantages of a PCM, a high meltenthalpy of the elements with a simultaneously narrow melt band shouldbe ensured. The specific heat capacity of thermal paraffins in the solidas well as liquid condition is roughly 2.1 kJ/(kg.K). Very good heatstorage properties result together with the melt enthalpy of 180 to 230kJ/kg of pure paraffin and that of 140 to 160 kJ/kg with agraphite-paraffin composite. Usually a high thermal conductivity isrequired for charging and discharging a latent heat reservoir. Thermalparaffins, as almost all organic substances however have a relativelylow thermal conductivity of only approx. 0.18 W/(m.K). This disadvantageis counteracted by way of adding graphite to the PCM. This measureconsiderably increases the thermal conductivity. Although PCMs have athermal conductivity which is about ten times worse that concrete, thenwith the addition of graphite of 100 to 150 kg per m³ of PCM, thethermal conductivity becomes about three times better than that ofconcrete. In order to increase the fire resistance of the elements andto avoid the exit of paraffin, the phase change material may be used inan encapsulated form, that is to say in suitable capsules whose wallthickness and volume are adapted to the requiremerts. A special case ofsuch an encapsulation is microencapsulating For this, the used paraffinsare enclosed in so-called microcapsules. Here it is the case of plasticcapsules with diameters between 5×10⁻⁶ m and 2×10⁻⁵ m. The meltedparaffin is firstly distributed in a fine manner by way of stirring itin water. With this, tiny paraffin droplets are formed, depending on thestirring speed and other parameters. The solid, very thin wall of themicrocapsule is produced around each one of these individual droplets ina so-called in-situ synthesis from plastic precursors. Themicroencapsuled paraffin may then be applied into different commerciallywidespread building materials in the manner of a powder, for example inthe inner plaster or filling masses. For its incorporation into athermoactive wall or ceiling element, the microcapsules filled withparaffin are stirred into a plaster mass and finely dispersed therein,so that they make up about 30% to 50% of the mass share of the total endmass. This mass, with a maximal thermal capacity of about 10 kJ/(kg K),is then inserted in such a wall or ceiling element as the effectivethermoactive element. The encapsulation of the PCM and the dispersion ina curing mass ensures that the paraffin may not exit. On account of thesmall size of the capsules, the total surface of the PCMs or paraffinsis very large. The microencapsulation therefore effects an optimal heatexchange between the PCM and the building material.

For encouraging a reliable heat exchange, the wall and ceiling elementsare designed such that larger surfaces are created in relation to thecontained PCM mass. This is achieved with a relatively low plank-likecasing 2. Furthermore one may also arrange heat-conducting ribs in theinside of the casing 2 so that in total an improved heat conductivityresults for the room which contains the phase change material 3. Anexpansion volume for unbonded PCM must always be provided in this closedcasing 2 in order to reduce excess pressure. The density of liquidparaffins lies between 750 and 850 kg/m³ depending on the meltingtemperature. Solid paraffins however have a density of 800 to 900 kg/m³.With a solid-to-liquid phase change, a maximal volume expansion of 10%results from this. One speaks of an undercooling of a phase changematerial if its solidification temperature lies below the meltingtemperature. At the same time however an undercooling in practise doesnot exist with a normal paraffin PCM—at least in comparison to otherlatent heat storage materials. A PCM during its lifetime or applicationmay undergo very many heating and cooling cycles. For this, thermalparaffins in contrast to many other PCMs are not very sensitive toageing and they are stable with regard to their cycle since no chemicalreactions occur during the storage operation in the storage material orwith respect to heat transport means and installation materials. Thermalparaffins are specifically inert with respect to almost all materials.Their very name describes their nature: “parum afinis” which means theyexhibit hardly any chemical reactions. Indeed the melting andsolidification of the paraffins is rather a purely physical procedure.For this reason the heat storage capacity remains at a constant levelduring the complete lifetime. Thermal paraffins are thermally stable upto 250° depending on the melting temperature. Paraffins do not boil evenat higher operating temperatures, i.e. no high vapour pressures arise.In the liquid condition, the viscosity is similar to that of water.Paraffin or wax is combustible, but the combustion temperature liessignificantly above 250°. Thermal paraffins are completely ecologicallysafe substances. They neither endanger water nor are they toxic orharmful to health. They may however be recycled and are biologicallydegradable.

If we now consider the initial condition of a wall and ceiling elementinstalled in a room in the morning of a hot summers day. The phasechange material in the casing 2 is solidified and the completethermoactive element is at a temperature of 21° C. for example. Thethermal connection between the viewed ceiling element 5, that is to saythe viewed ceiling sheet [metal] (plate), and the casing 2, is ensuredby the heat contact body 24. If the room temperature increases only alittle then heat begins to flow through the viewed ceiling element 5 andthe heat contact body 24 into the casing 2 and here the phase changematerial 3 begins to slowly liquefy. Thus heat is extracted from theroom without any cooling output which consumes energy becomingnecessary. The absorbed heat is simply stored in the phase changematerial of the casing 2. In this manner, at night, stored heat may beled away to a natural heat sink, by which means the phase changematerial 3 is again solidified and is ready to take up heat again duringthe coming day. If one can foresee that a significant cold front iscoming, then one does away with the leading-away of heat. The sameapplies to the case that during the night the temperature in the room isreduced to such an extent that the room is considered to be too cold topleasantly work in. In this case the heat from the casing is deliveredto the room again in the reverse direction via the viewed ceilingelement 5. In this manner the room temperature may be maintained duringthe day to within narrow limits without any energy expense. Additionalheat may be supplied or led away by way of the heating and cooling pipe1, according to requirements, for encouraging the heat exchange with theroom or for activating a heat flow between the room and the phase changematerial 3. If the temperature of the outer surroundings which reducesduring the night is not sufficient to cause the liquefied phase changematerial to solidify until the following morning, then one may aid thiswith cooling water from a natural heat sink, which for this purposecirculates through the heating and cooling pipe 1. Completelyindependently of the function of the phase change material, with regardto the heating and cooling pipe 1, when required one may of coursesupply heat to the room from a heat source or lead away heat from theroom to a heat sink. The lamellar design 8 is thermally separated fromthe casing 2 for such a direct cooling and heating. The casing 2 withthe phase change material acts as much as possible as a heat reservoirand helps to dispense or take up heat shifted in phase with regard tothe temperature course over 24 hours.

FIG. 3 shows a third variant of the thermoactive wall and ceilingelement. Here it is shown in cross section. In the inside of the casing2 the heating and cooling pipe 1 is formed running along the lower sideof the casing out of the casing material as a flow path in thelongitudinal direction of the casing 2 or of the section. This heatingand cooling pipe 1 is therefore connected to the casing 2 in astationary manner and directly belongs to this casing. It thereforeconsists of the same material as the casing and when required may havean insert pipe of copper. On the lower side of the casing 2, lamellae 9are arranged in the longitudinal direction of the casing, between whicha sound absorption material 4 is inserted for improving the acoustics ofthe room. The complete design shown here is closed from the bottom byway of a perforated ceiling sheet [metal] (plate) as a viewed ceilingelement 5. This viewed ceiling element 5 is stuck onto the lower edgesections of the lamellae 9 by way of a claiming mechanism ofspring-steel clips 6. Furthermore a contact layer 28 is deposited ontothe lower edges of the lamellae 9, which contributes to an improvedheat-conducting connection of the connection since indeed heat issignificantly taken up from the room via the perforated ceiling sheet[metal] (plate) and when heating is required, this heat is dispensedagain to this. With regard to this contact layer 28, it may be the caseof a thermally conductive foam material which may be compressed. Thepassage of heat is sufficiently large even with a very moderatethermally conductive properties, on account of the low thickness of thematerial. A fundamentally good heat transfer from the ceiling sheet[metal] (plate) or from the viewed ceiling element 5 to the lamellae 9on the lower side of the casing is decisive. In one variant, steel woolmay take the place of the sound absorption material which likewise has asound-absorbing effect even if very low, but is also a good heatconductor. In this case the lamellae 9 are superfluous and the viewedceiling element 5 is merely fastened to the edge of the casings. Agroove 7 which is T-shaped in cross section is arranged on the upperside of the casing 2 with which the casing 2 by way of angle sectionsmay be fastened to an associated support design in the form of a squaretube 16 with a longitudinal slot 17. The angle sections 15 are fastenedon the groove 7 with screws, wherein the heads of the screws 12 areseated in the groove 7 secure against rotation. The lateral elongateholes 11 on the angle sections permit the height or the distance of thecasing 2 to the ceiling to be adapted and to compensate anyirregularities. The angle sections 15 are mounted onto a square tube 16with a central longitudinal slot 17, said tube on the building sidebeing pre-assembled on the ceiling, as this is shown in FIG. 3. Aceiling element in this case is fastened transversely to itslongitudinal direction on at least two such square tubes 16 arranged ina parallel manner.

A fourth variant of a thermoactive wall and ceiling element is shown incross section in FIG. 4 which likewise is equipped with sound-absorptionmaterial 4 on the room side. The heating and cooling pipe 1 here is notdirectly outwardly formed from the material of the casing but runswithin a channel 13 in the lower side of this casing 2 in aheat-conducting manner, and this channel extends along the casing 2. Thecasing 2 on its lower side likewise comprises lamellae 9 projectingdownwards between which a sound-insulating material 4 is laid. In onevariant, again steel wool may be used for the sound absorption material4. In this case the lamellae are superfluous and the perforated ceilingplate as a viewed ceiling element 5 is merely fastened to the edges ofthe casing. The actual heating and cooling pipe 1 is fastened on theperforated ceiling sheet [metal] (plate) in a heat-conducting manner viaa support web 14. Here it may be the case of a steel or aluminium tube 1which when required may also be equipped with an insert tube of copper.The lower edge of the support web 14 is soldered, welded or bonded ontothe perforated ceiling sheet [metal] (plate) or viewed ceiling element5, by which means a heat bridge to the viewed ceiling element 5 iscreated. The viewed ceiling element 5 together with the heating andcooling pipe 1 is stuck onto the casing 2 from below, by which means aheat-conducting connection between the pipe 1 and the channel 13 in thecasing 2 arises. At the same time the viewed ceiling element 5 may beprovided with spring steel clips 6 by way of which it may be simplyfastened to the lamellae 9 of the casing 2 by clipping on, after thepipe 1 of the individual wall and ceiling elements have been connectedto one another by way of soldering or by way of tube bends capable ofbeing coupled, or flexible tubing connections. If required, the viewedceiling elements 5 may thus be easily removed. A groove 7 is admitted onthe upper side of the casing 2, with which the ceiling element may befastened to a support. design 16 which fits with this, as has alreadybeen described with regard to FIG. 3. This variant of the wall andceiling element is also suitable for retrofitting a cooling ceilingwhich already has a viewed ceiling plate as well as a cooling tube whichis connected to the viewed ceiling plate in a heat conducting manner. Inthis case one merely changes the construction above the cooling tube. Acasing 2 with phase change material 3 is installed above each coolingtube. The casing 2 on its lower side comprises a channel in which thealready present cooling tube comes to lie in a heat-conducting manner,wherein the perforated viewed ceiling may otherwise be further made useof. This thermoactive wall and ceiling element may furthermore be alsoinstalled onto walls in the same manner as onto room ceilings.

Yet a fifth variant of,the thermoactive wall and ceiling element isshown in cross section in FIG. 5. With this variant the heating andcooling pipe 1 is integrated in section material and as a peculiaritythe sound absorption material 4 is arranged above the casing 2. Withthis embodiment, the heat conducting lamellae between the lower side ofthe casing 2 and the ceiling sheet [metal] plate 5 which is notperforated in this case are done away with. The viewed ceiling element 5in one variant may also be formed by a layer of plaster or a plasterplate. Pipes arranged with a material fit with the casing may take theplace of a heating and cooling pipe 1. Such ceiling elements with whichthe sound absorption material 4 is arranged above the casing 2 are laidsuch that in each case a gap is set free (created) between theindividually assembled ceiling elements so that the sound impinges thesound absorption material 4 arranged above the ceiling elements, throughthese gaps, and is absorbed by this material. If in contrast onecompletely does away with the sound absorption capability and leaves outthe sound absorption material, one may then make do without any distancebetween the elements and the insulation layer. This variant is thenparticularly suitable for wall installation.

A variant is shown in FIG. 6, with which the heating and cooling pipe 1run within the casing 1 and are formed by a commercially availablecapillary tube mat 29. Such capillary tube mats may be fabricated in anylengths or widths are for example are layered into the casing 2 in thelongitudinal direction, whereupon the phase change material 3 is filledwhich then encloses the tubes of the capillary tube mat 29.

The wall and ceiling elements may be intalled as shown in FIG. 3 and 7if they comprise a groove 7 with a T-shaped cross section on their upperside. A hexagonal screw head of a screw 12 fits into this groove 7 sothat the screw 12 projects upwards out of the groove 7 and is held in itin a rotationally secure manner, but displaceable along the groove 7.The horizontal limb of the angle section 15 is pushed over the screw 12and is secured with a nut 20 which belongs to the screw. The limb of theangle section 15 projecting upwards comprises a vertical elongate hole11 which is passed through by a screw 18 whose hexagonal head fits intoa square section 16 with a lateral longitudinal slot 17 in a mannersecure against rotation, so that it is rotatably held therein. Thus theangle section 15 may be displaced along the square section 16 and may beadjusted in height by the length of the elongate hole 11. For fastening,one yet only needs to tighten the nut 19 belonging to the screw 18. Thesquare section 16 by way of anchor bolts is previously assembled onto aceiling to be equipped. Thus the ceiling element may be displaceablyaligned and fastened in two directions on this square section 16.

The wall and ceiling elements on their upper side, instead of a groove 7may comprise an upwardly projecting angle section 10 as is to be deducedfrom FIG. 5 and is shown perspectively in FIG. 8. The wall and ceilingelement may be furnished with sound absorption material on both sides ofthe angle section. An angle section 15 is screwed onto this anglesection 10, and this piece in each limb comprises a vertically runningelongate hole 11. The angle section 10 on the upper side of the casing 2comprises such a groove which accommodates a screw head in arotationally secure manner, wherein however the screw remainsdisplaceable along the groove. The horizontal limb of the angle sections15 is fastened on the lower side of a square tube 16 which comprises alongitudinal slot 17 on this lower side and was previously assembledonto the raw ceiling. The longitudinal slot 17 allows a screw with itshead to be inserted into the square tube 16 so that the screw head 12 isheld therein secure against rotation, whilst the screw projectsdownwards through the longitudinal slot 17 and is displaceable along thesquare tube 16.

A particular embodiment of the thermoactive wall and ceiling element isshown in FIG. 9. The edge regions of the casing 2 are raised and aresealingly closed at the corners. Here one sees the casing 2 without alid, and the heat conducting ribs 30 which run therein in thelongitudinal direction and which are connected along their lower side tothe base plate of the casing 2 in a heat-conducting manner. With this itmay be the case of aluminium angle sections which with transverse struts35 form a grid. The lower, horizontally running limb of the sections byway of a special adhesive tape are the bonded to the base plate of thecasing in a heat-conducting manner. These heat conducting ribs 30 aredistanced to one another by approx. 30 mm and the conduit loops 29 ofthe capillary mat 29 run between them. At least one individual conduitloop 29 runs in each case between two heat conducting ribs 30. For thisthe capillary mat 29 may merely be inserted into the casing 2 which isstill open at the top so that the wall and ceiling element is in thecondition shown here. On the capillary mat 29 one may recognise theupwardly directed supply union 31 and the oppositely lying dischargeunion 2. The casing 2 is then filled with a pasty caster mass, whereinapprox. 30% to 50% of its mass consists of microencapsulated phasechange material. With this the material is finely distributed over thewhole contents of the casing. After filling the casing, the mass isscraped flat and then cures. At the end, the element is closed at thetop with a lid (cover) of zinked sheet metal of approx. 0.75 mmthickness and is riveted at the edges. At the rear, the edge region isfolded off to the outside so that a mounting fold is formed here whichpermits the simple installation of the element to a ceiling. Theinstallation is accomplished as follows: a flexible tubing conduit isconnected to the unions 31, 32 by way of a plug connection. Subsequentlythe element with its rear fold-up is suspended on an assembly strip onthe ceiling and afterwards the front corners of the casing 2 are pivotedup by way of a pull cable and fastened. The fastening angles 34 at thesame time serve for suspending the pull cable and for fastening thecasing 2 to the ceiling.

Irrespective of how these wall and ceiling elements are designed, ineach embodiment they may be treated with special commercially availablefireproof materials for increasing their resistance to fire. Thus forexample a fire protection coating which given the effect of fire andheat forms a heat-insulating insulation layer is suitable. The casingmay also be coated with a fireproof gel for example of awater-containing alkali silicate with a weight ratio of SiO₂ to Na₂O of2.7-3.5 and glycerine content of 5-15% by weight. Furthermorefire-retarding polyolefins for example from the product series Exolit®from Claraint GmbH in D-65840 Sulzbach is also suitable for coating thecasings. As one variant, the complete mass of the carrier mass and theencapsulated phase change material may be intermixed with afire-retardant substance or with filler of a high heat thermal capacityacting as a heat sink. Additionally, in the case of a fire, the coolingof the ceiling elements either with the integrated pipe system or withan external water system, for example with a sprinkler installation areconsidered, which is in heat conducting contact with the ceilingelements or may be brought into contact with them. This has theadvantage that whole walls and ceilings may be effectively cooled in thecase of fire.

The basic concept behind all these thermoactive wall and ceilingelements is to permit a heat exchange between the room and the heatexchange material 3 which is provided, in order to be able to lead awaythe heat with a time delay to a natural heat sink which is lateravailable as a result of temperature fluctuations, or if required to beable to use this heat again. This heat exchange of course makes senseabove all between cool and hot time phases, thus between day and nightor at times of rapid hot and cold incursions with a rapid reversal. Iffor example heat is supplied to a room during the day as a result of theradiation from the sun, the use of various electrical apparatus as wellas the presence of many persons in the room, then one must cool thisroom in order not to allow this temperature to increase beyond acomfortable range. Now a highly efficient heat exchanger mass is createdwith the thermoactive wall and ceiling elements which has otherwise beenlacking. On account of the low melting temperature of 22.5° C. of thespecially conditioned PCM, the heat led through the cooling ceiling to agreat extent is stored in the heat reservoir of the wall and ceilingelements by way of causing the PCM to melt. This procedure last forseveral hours until the PCM is completely liquefied. If heat is to becontinued to be led away, then this is dispensed to an external heatsink. If a cold front unexpectedly occurs and the room temperaturethreatens to sink, the flow of heat is reversed. The PCM specificallybegins to solidify with a slight drop in temperature whilst giving offits latent heat to the room via the viewed ceiling elements 5 which thenact as a heat cover. The process of solidification also occurs whenwater circulates through the pipe 1 and removes latent heat from thePCM. Thus basically the heat which is removed from the room by coolingis stored in the wall and ceiling elements and may either later bedispensed to a natural heat sink outside the room or may be dispensed tothe room again. Since the heat exchange is effected in a slow manner andlasts for several hours, it is predestined for the intermediate storageof heat between day and night or between office work and idle times.

Agilely acting designs of these thermoactive wall and ceiling elementshelp with extreme fluctuations of temperature caused by the weather orwith large changes of the heat loads in the course of the day.Specifically, with those embodiments where the heating and cooling pipe1 is not connected to the casing 2 or is not outwardly formed by it asone piece, one may provide a movement mechanism in order to temporarilydecouple the rib system 9 with the viewed ceiling element 5 from thecasing 2 which indeed contains the heat storage element in the form ofthe phase change material 3. This may effected eitherelectromechanically, thermoelectrically, electrochemically, by way of anelectrical field or hydraulically. The drive means may include electricmotors, magnetic force cylinders, electrochemical actuators ECA,electroactive polymers EAP, hydraulic force cylinders or a motor-drivenpull cable. By way of displacing the rib system 9 by a few mm downwardsor lifting a heat contact body 24 from the casing 2, the material fitwith the phase change material 3 is interrupted and the heat transportis greatly limited. In this decoupled condition the room may be suppliedwith large quantities of heat by way of the heating and cooling pipes 1and the viewed ceiling elements 5, or reversely, large quantities ofheat may be led away from the room so that a great heating and coolingoutput is available when required. If one heats in a high-output manner,then the heat via the viewed ceiling elements 5 directly reaches theroom and only a very small share flows into the phase change material 3.Reversely, if one greatly cools then heat flows from the room into theviewed ceiling elements 5 and is transported away via the cooling pipes1 without it being stored in the phase change material. By way of thisdecoupling of the storage layer, that is to say the casing 2 filled withPCM, from the actual heating and cooling elements, specifically theviewed ceiling elements which face the room, the system becomesthermally agile and by way of this behaves similar to a conventionalcooling cover. In a room whose ceiling or walls are completely or partlylined with such thermoactive wall and ceiling elements, one may rapidlychange the temperature to any value by way of the direct cooling andheating. An individual regulation of the room becomes possible by way ofthis.

List of Reference Numerals

-   1 heating and cooling tube-   2 sheet [metal] casing-   3 phase change material PCM-   4 sound absorption material-   5 view ceiling element-   6 spring steel clips-   7 T-shaped groove on the upper side of the sheet metal casing 2-   8 lamellar design-   9 lamellae on the lower side of the sheet metal casing-   10 support design-   11 elongate holes on the support design-   12 vertical screw on the angle section 15-   13 channel on the lower side of the sheet metal casing-   14 support web for the heating and cooling tube, connected to the    ceiling plate-   15 angle section for assembly-   16 square tube for installation onto the ceiling-   17 longitudinal slot-   18 transverse screw on the angle section 15-   19 screw nut for the transverse screw 18-   20 screw nut for the vertical screw 12-   21 cover-   22 side wall, thermal separation wall-   23 cavity-   24 heat contact body-   25 movement sheet [metal] (plate)-   26 drive means-   27 air gap between the heat contact body 24 and the casing 2-   28 contact layer-   29 capillary tube mat-   30 heat conducting ribs-   31 supply union for capillary mat 29-   32 discharge union for capillary mat 29-   33 suspension edging-   34 fastening angle-   35 transverse struts for grid of angle sections.

1-9. (canceled).
 10. A thermoactive wall and ceiling element forinstallation in rooms of new and existing buildings, comprising a closedcasing for intermediately storing heat and containing a phase changematerial, as a latent heat reservoir, and at least one heating pipe andcooling pipe for controlling a heat exchange between said closed casingand its surroundings, wherein said phase change material is based upon aparafin or a salt hydrate for increasing thermal conductivity in asurrounding region of said phase change material with heat conductingribs being added to said phase change material for increasing heatconduction capability, said heat-conducting ribs being arranged inheat-conducting contact with said closed casing, between which said atleast one heating pipe and cooling pipe of a capillary tube mat extend,said capillary tube mat having connections that are led through a lid ofa casing for insert connections, with a remaining side of said closedcasing filled with a plaster as a carrier mass, wherein said phasechange material is encapsulated in plastic capsules is dispersed, andwith a viewed ceiling element being arranged on a lower side of saidclosed casing.
 11. The thermoactive wall and ceiling element forinstallation in rooms of new and existing buildings according to claim10, wherein said phase change material further includes graphite. 12.The thermoactive wall and ceiling element for installation in rooms ofnew and existing buildings according to claim 10, wherein said closedcasing on an outer side includes a coating having a flame-inhibitingsubstance.
 13. The thermoactive wall and ceiling element forinstallation in rooms of new and existing buildings according to claim12, wherein flame-inhibiting substance is a fireproofing gel.
 14. Thethermoactive wall and ceiling element for installation in rooms of newand existing buildings according to claim 10, wherein saidflame-inhibiting substance is added to said carrier mass.
 15. Thethermoactive wall and ceiling element for installation in rooms of newand existing buildings according to claim 10, wherein saidflame-inhibiting substance is added to said phase change material, asencapsulated.
 16. The thermoactive wall and ceiling element forinstallation in rooms of new and existing buildings according to claim10, further comprising fillers having a high heat capacity acting as aheat sink added to said carrier mass and said phase change material, soencapsulated.
 17. The thermoactive wall and ceiling element forinstallation in rooms of new and existing buildings according to claim10, further comprising a heat-conducting lamellar with said at least oneheat pipe and cooling pipe integrated into said heat-conducting lamellarand having a vertical lamellae between which a sound absorption materialis applied and on lower edges of said sound absorption material is saidviewed ceiling element as a viewed ceiling and further comprising a heatexchanger on a room side detachably fastened, is assembled viaheat-insulating side walls onto the lower side of said closed casingwhile leaving a cavity, a heat-conducting heat contact body beingarranged in said cavity with said heat-conducting contact body beingconnected in a heat-conducting manner to a heat-conducting connectionwith said lower side of said closed casing and an upper side of saidheat-conducting lamellar, and drive means for displacing or compressingsaid heat-conducting heat contact body inside of said cavity, so thatsaid heat-conducting connection with said closed casing, with saidheat-conducting lamellar, or with both said closed casing and saidheat-conducting lamellar is temporarily separated.
 18. The thermoactivewall and ceiling element for installation in rooms of new and existingbuildings according to claim 17, wherein said lower side of said closedcasing forms an oblique plane having a heat contact layer, and awedge-like, heat-conducting heat contact body is horizontallydisplaceably arranged in said cavity, said wedge-like, heat-conductingheat contact body having a lower side in a heat-conducting connectionwith said upper side of said heat-conducting lamellar, and which saidupper side runs parallel to said lower side of said closed casing, withsaid drive means being accommodated in said cavity, by way of which saidwedge-like heat-conducting contact body is displacable inside of saidcavity, so that, when required, said wedge-like heat-conducting contactbody is able to be brought in a heat-conducting connection with, or bethermally separated from, said lower side of said closed casing.
 19. Thethermoactive wall and ceiling element for installation in rooms of newand existing buildings according to claim 17, wherein saidheat-conducting heat contact body in said cavity includes an elasticallycompressible material having an expanded condition and, wherein in saidexpanded condition, is in a heat-conducting connection with said lowerside of said closed casing and with said upper side of said lamellar andis passed through horizontally via a movement sheet vertically movablevia said drive means, so that either said upper side of saidheat-conducting heat contact body, when required, is capable of beingbrought into a heat conducting connection with, or able to be thermallyseparated from, said lower side of said closed casing, or said lowerside of said heat-conducting heat contact body, when required, iscapable of being brought into a heat-conducting connection with, orcapable of being thermally separated from, said upper side of saidlamellar.
 20. The thermoactive wall and ceiling element for installationin rooms of new and existing buildings according to claim 17, whereinsaid drive means for displacing said heat-conducting heat contact body,or for compressing and expanding said heat-conducting contact body, iselectrochemical actuators, electroactive polymers, thermoelectric driveelements, electric motors, motorically driven pull cables, magnetic orhydraulic force cylinders or electroreological fluids.
 21. Thethermoactive wall and ceiling element for installation in rooms of newand existing buildings according to claim 10, wherein said closed casingcomprises a section having a rectangular cross-section closed on bothsides in a fluid-tight manner via a lid, said closed case having in saidlower side a channel, with a lamellae arranged on said lower side ofsaid closed casing projecting perpendicularly therefrom, between which asound absorption material is applied, said viewed ceiling element beinga viewed ceiling is detachably fastened on lower edges of said lamellae,said viewed ceiling element, via a support web, carrying said at leastone heating pipe and cooling pipe running in said channel via a materialfit.
 22. The thermoactive wall and ceiling element for installation inrooms of new and existing buildings according to claim 10, furthercomprising a sound absorption material arranged on an upper side of saidclosed casing with a support design passing through said soundabsorption material.
 23. The thermoactive wall and ceiling element forinstallation in rooms of new and existing buildings according to claim10, wherein said closed casing comprises a section having a rectangularcross-section and closed on both sides in a fluid-tight manner via alid, said at least one heating pipe and cooling pipe being integratedeither inside said section or into a lamellae, which on said lower sideof said closed casing either rigidly belonging to said closed casing orassembled on said closed casing in a mobile manner, projectperpendicularly from said section, and further comprising a soundabsorption material applied between said lamellae, and said viewedceiling element being detachably fastened on lower edges of saidlamellae via spring clips.